Behavior of protein-polysaccharide conjugate-stabilized food emulsions under various destabilization conditions

The sensitivity of protein-stabilized emulsions to flocculation, coalescence, and phase separation under destabilization conditions (i.e., heating, aging, pH, ionic strength, and freeze-thawing) may limit the widespread use of proteins as effective emulsifiers. Therefore, there is a great interest in modulating and improving the technological functionality of food proteins by conjugating them with polysaccharides, through the Maillard reaction. The present review article highlights the current approaches of protein-polysaccharide conjugate formation, their interfacial properties, and the behavior of protein-polysaccharide conjugate stabilized emulsions under various destabilization conditions, including long-term storage, heating and freeze-thawing treatments, acidic conditions, high ionic strength, and oxidation. Protein-polysaccharide conjugates are capable of forming a thick and cohesive macromolecular layer around oil droplets in food emulsions and stabilizing them against flocculation and coalescence under unfavorable conditions, through steric and electrostatic repulsion. The protein-polysaccharide conjugates could be therefore industrially used to design emulsion-based functional foods with high physicochemical stability.